Unfortunately, many standard leases require that three-quarters of the floor in every room be carpeted to reduce sound in adjacent apartments, and daily vacuuming is a big task for the housewife with small children. Which is only to say that taking charge of one’s asthma is not an easy matter.
Dust mite is a common indoor year-round allergen; allergy to dust mite has been associated with allergic rhinitis and asthma in children, as well as in adults. If you or your child are diagnosed with an allergy to dust mite, your physician will likely advise you on measures you can take to reduce your exposure to dust mite.
Dust mites are eight-legged arachnids related to the spider family. Their cast skin and fecal matter are two constituents of house dust that many people are allergic to. Dust mites live indoors and are present in nearly all homes in areas where the relative humidity is 50% or greater for much of the year. Dust mites are microscopic; you cannot see them without a magnifying microscope. They thrive in warm, dark, humid environments, and live off flecks of human skin. They do not drink free water, but absorb moisture from the surrounding environment. They are often found in bedding, in upholstered furniture, and in carpeting and draperies. They are fairly ubiquitous in the United States, and their presence in a home in no way implies poor housekeeping.
That said, we know of several ways to reduce a person’s exposure to dust mites. First, dust mites cannot survive at a high altitude or in very dry environments. Could that be why, several generations ago, asthmatics were often sent “to the desert” or “to the mountains” to gain a respite from their symptoms? Was the relocation no more than a move to an area free of dust mite allergen? On a more practical note, ways to reduce your home’s dust mite burden includes removing carpeting and heavy cloth draperies. Consider washable curtains or blinds. Avoid overstuffed furniture made of fuzzy fabric. An alternative to removing carpeting involves thorough, daily carpet vacuuming with a high-quality vacuum cleaner, possibly one fitted with a HEPA filter. Steam clean or shampoo carpets and rugs at least once a year.
The bedroom merits special attention. Most of us spend at least 7 hours out of 24 sleeping in bed, with our head on a pillow or two, wrapped up in sheets, blankets and comforters. Bedding is a favorite location of dust mites. So, while we blissfully slumber away, we are in close contact with dust mite antigen, inhaling allergic material all night long. The solution? To interrupt the replication of dust mites, while reducing the amount of allergen that reaches us. The first goal is easy to achieve: since the dust mites have a life cycle of 2 weeks and cannot survive elevated temperatures, simply launder sheets, mattress pads, and washable blankets in hot water at least once every two weeks. Hot water is water heated to a temperature of at least 130°F. The hotter, the better! Items that cannot be washed frequently, such as pillows, comforters, and mattresses and box springs, are best encased in specially designed covers.
The allergen impermeable covers are available from retailers specializing in allergy products. If your physician advises you to encase your bedding, make certain the covers you purchase are rated for dust mite protection. Most covers are of high quality and are unobtrusive; you won’t even know you’re sleeping on one. They usually require washing once a year, and carry a warranty for up to 20 years of use. Stuffed animals are dust mite magnets, and many children love to collect and sleep with them. Encourage your child to keep the collection in a location other than the bedroom and consider identifying one “special” stuffed toy to sleep with. Then, if possible, launder the favorite in your washing machine in hot water every two weeks, just as you would bedding. Unfortunately, not all stuffed animals are machine washable. Despair not! Plan “B” involves placing the furry toy in a sealed plastic bag, and placing the stuffed animal in your freezer for 24 to 48 hours once or twice a week.
Should someone with dust mite allergy invest in an air purifier? Be sure to ask your physician or allergist before buying one. Among the options currently available, only a few have been studied in the medical (as opposed to the industrial) literature. Machines that are designed to filter the air in an enclosed space through a fine, high-efficiency particulate air (HEPA) filter are, if used correctly, very efficient in trapping particles of a defined size (usually as small as 0.3 microns). HEPA filters thus reduce the airborne concentration of microscopically small airborne particles, including many aeroallergens, like pollens and dust mites. HEPA-filtering machines must be selected based on the square footage of the enclosed space they will filter.
The machines usually contain both a carbon pre-filter, and a true HEPA filter. The pre-filter should be changed every 3 to 6 months, and the HEPA filter should be replaced every year. HEPA filters are expensive but effective. HEPA filter units do not require much maintenance, apart from filter changes and are engineered to run 24 hours a day. They have the disadvantage of being rather noisy, and they do tend to dry the ambient air. The correct way to run a HEPA unit is to close the room’s windows and doors, and set the unit’s fan on “high” when you are not home. When you are in the room, at night, for example, set the unit’s fan on the highest level you can tolerate from the perspective of noise.